CONNECTOR, OPTOELECTRONIC COMPONENT AND METHOD FOR MANUFACTURING A CONNECTOR OR AN OPTOELECTRONIC COMPONENT

Abstract

A connector carrier (10) is specified, comprising: a base body (1) formed from a plastic material; a conductor track (2) having a bottom surface (2a) facing the base body (1), a top surface (2b) facing away from the base body (1), and a side surface (2c) connecting the bottom surface (2a) and the top surface (2b), wherein the conductor track (2) is in direct contact with the base body (1) at the bottom surface (2a) and the side surface (2c). The connector carrier can be used, for example, in an optoelectronic component comprising a micro-LED.

Description

A connection carrier, an optoelectronic component and a method for producing a connection carrier or an optoelectronic component are specified.One object to be achieved is to specify a connection carrier and an optoelectronic component which are particularly mechanically stable. A further object to be achieved is to specify a corresponding method for production.According to at least one embodiment, the connection carrier comprises a base body. The base body is in particular the mechanically load-bearing) component of the connection carrier, on which further components of the connection carrier can be mechanically fastened.The base body can be designed, for example, as a rigid plate or flexible film. For example, the base body has a rectangular parallelepiped shape. The base body is formed with a plastic material. That is to say that the base body can contain the plastic material or consist of this.According to at least one embodiment, the connection carrier comprises a conductor track. The conductive path is an electrically conductive structure formed with an electrically conductive material such as a metal.The conductor track can be rectangular-shaped, at least in sections. The conductor track runs, for example, along a straight and / or curved line.The conductor track can serve for distributing electrical current on the connection carrier. Furthermore, the conductor track can serve as a contact point on which a component is mechanically and electrically fastened.The conductor track has a base surface facing the base body, a cover surface facing away from the base body and a side surface connecting the base surface and the cover surface. It is possible here for the conductor track to comprise a plurality of such side faces.Furthermore, it is possible for the connection carrier to comprise two or more conductor tracks which are formed similarly to one another, that is to say are formed with the same material, for example, within the scope of the production tolerance and have the same thickness within the scope of the production tolerance. The thickness is measured in a vertical direction which runs perpendicular to the main extension direction of the connection carrier.According to at least one embodiment of the connection carrier, the conductor track is in direct contact on the bottom surface and the side surface with the base body and thus with the plastic material of the base body. This means that the conductor track is in direct contact with the base body, for example, on the entire base surface. Furthermore, it is possible for one side surface or, if appropriate, all side surfaces of the conductor track to be in direct contact with the base body. The bottom surface and the side surface are wetted here, for example, with the plastic material of the base body.According to at least one embodiment, a connection carrier is specified witha base body formed with a plastic material,a conductor track having a bottom surface facing the base body, a top surface facing away from the base body and a side surface connecting the bottom surface and the top surface, whereinthe conductor track is in direct contact with the base body on the bottom surface and the side surface.The conductor track can have, for example, a small width of in particular at most 10 μm, measured in a main extension plane of the connection carrier. Alternatively or additionally, it is possible for the conductor track to have a thickness of in particular at most 500 μm or at most 250 μm or at most 10 μm.In particular in the case of conductor tracks which are applied to a base body which is formed with plastic, there are often only low connecting forces between the conductor track and the base body. This is the case all the more with thin conductor tracks with a small width, which correspondingly have a bottom surface with a small surface area.If electronic components are fastened to these conductor tracks, shear forces which can occur as a result of encapsulation or lamination or temperature fluctuations prove to be critical, since as a result at least a part of the conductor track can be detached from the main body. Due to this restriction, it is not possible, for example, to encapsulate light-emitting diode chips which are fastened to such a connection carrier by means of an injection molding method.The connection carrier described here now makes use of the concept that direct contact of the conductor track with the base body leads not only on the base surface but also on the side surface of the conductor track to better anchoring of the conductor track in the base body and thus shear forces which occur in particular can no longer lead to detachment of the conductor track from the base body or can lead only with reduced probability. Furthermore, the temperature during the application of the metallic conductor tracks is limited by the base body, since PET is only temperature-stable to a limited extent, for example. This leads to a non-optimum adhesion of the conductor tracks to such substrates.According to at least one embodiment of the connection carrier, the side surface is covered at least to an extent of 50% or more, in particular completely, with the base body and thus, for example, with the plastic material of the base body, wherein the cover surface of the conductor track remains free of the base body and thus, for example, of the plastic material. In this way, the conductor track can be anchored in the base body in a particularly stable manner without plastic material on the cover surface of the conductor track making it more difficult for electronic components to be connected to the conductor track.According to at least one embodiment of the connection carrier, the conductor track is printed on the base body. The connection carrier can then be in particular a printed conductor track. The connection carrier can be formed as a whole flexibly, for example as a film, and be formed by a printed circuit board.According to at least one embodiment, the base body is designed to be radiation-transmissive. The base body can be designed to be transmissive in particular for electromagnetic radiation in the wavelength range between infrared light and UV radiation, in particular for visible light. For example, the base body is designed to be transmissive to visible light and / or infrared radiation.Such a connection carrier is particularly well suited for the connection of light emitting diodes and, for example, for the formation of light-transmissive or transparent displays.According to at least one embodiment of the connection carrier, the conductor track contains copper or the conductor track consists of copper. Such conductor tracks can be applied to the base body in a particularly simple manner, for example by printing, and benefit particularly strongly from the better anchoring of the conductor track in the base body due to a partial covering of the side surface with material of the base body.According to at least one embodiment of the connection carrier, a plurality of conductor tracks is applied to the base body. By means of the plurality of conductor tracks, it is possible, for example, to mechanically fasten a plurality of electronic components to the connection carrier and to electrically connect them there.According to at least one embodiment of the connection carrier, it is possible for the conductor tracks to be arranged at least in places in a network-like manner. This means that the different conductor tracks can in particular intersect or cross. In this case, the conductor tracks on the upper side of the base body can form, for example, a net-like pattern in which a multiplicity of conductor tracks extend parallel to one another along a first direction and a multiplicity of conductor tracks extend along a second direction which runs transversely or perpendicularly to the first direction.An optoelectronic component is also specified. The optoelectronic component described here comprises in particular a connection carrier described here, such that all features disclosed for the connection carrier are also disclosed for the optoelectronic component and vice versa.According to at least one embodiment of the optoelectronic component, the optoelectronic component comprises an optoelectronic component which is connected to the connection carrier on the cover surface of the conductor track in a mechanically and electrically conductive manner.For example, it is possible for the optoelectronic component to be connected mechanically and electrically to the connection carrier by soldering and thus by a soldering material arranged between the optoelectronic component and the conductor track. Alternatively, a conductive adhesive may be arranged between the optoelectronic component and the conductor track.In particular, the optoelectronic component then comprises a plurality of components which are connected to a plurality of conductor tracks.The optoelectronic component can be, for example, a radiation-emitting component such as, for example, a laser diode or a light-emitting diode. Furthermore, it is possible for the optoelectronic component to be a detecting component such as a photodiode, for example.According to at least one embodiment of the optoelectronic component, the optoelectronic component is a micro-LED or mini-LED or comprises a micro-LED or a mini-LED.As a broad definition, a micro-LED can be seen as any light emitting diode (abbreviated "LED")-generally no laser-of particularly small size.As a rule, this is also an important criterion in addition to size, a growth substrate is removed in the case of micro LEDs, so that typical heights of such micro LEDs are, for example, in the range from 1.5 μm to 10 μm, including limits. In contrast, mini-LEDs still adhere the growth substrate, resulting in a thickness of about 50-100 μm.In principle, a micro LED does not necessarily have to have a rectangular radiation emission surface. In general, for example, an LED with a radiation emission surface can be used, in which, in a plan view of the layers of the layer stack, each lateral extent of the radiation emission surface is smaller than or equal to 100 μm or smaller than or equal to 70 μm, including boundaries.For example, in the case of rectangular micro LEDs, an edge length-in particular in plan view of the layers of the layer stack-of less than or equal to 70 μm or less than or equal to 50 μm is frequently mentioned as a criterion.Usually, such micro LEDs are provided on wafers.At present, primarily displays are considered as applications of micro-LEDs. In this case, the micro-LEDs form pixels or subpixels and emit light of a defined color. Due to the small pixel size and a high density with a small spacing, micro-LEDs are suitable, inter alia, for small monolithic displays for AR applications, in particular smart glasses. In addition, further applications are being used, in particular the application in data communication or even pixelated lighting applications.The literature contains various notation for micro-LEDs, for example μLED, μ LED, μLED, μ LED or micro light emitting diode.Furthermore, a method for producing a connection carrier or an optoelectronic component is specified. By means of the method described here, in particular connection carriers and optoelectronic components described here can be produced. That is to say that all features disclosed for the connection carrier and the optoelectronic component are also disclosed for the method and vice versa.According to at least one embodiment of the method, a base body is provided which is formed with a plastic material. The base body is, for example, a plate which can be rigid or a film which is flexible.According to at least one embodiment, a conductor track is applied to an upper side of the base body. In particular, a plurality of conductor tracks is applied to the upper side of the base body. For example, the conductor tracks are fastened to the upper side of the base body by a printing method.According to at least one embodiment of the method, the conductor track is heated, so that by means of heat transfer from the conductor track to the base body, the plastic material of the base body in the vicinity of the conductor track softens and the conductor track dips into the base body or the base body surrounds it.In this way, a side surface of the conductor track can be brought into direct contact with the base body, so that the conductor track is in direct contact with the base body on its bottom surface, which faces the base body, and on its side surface, which connects the bottom surface to a top surface of the conductor track facing away from the bottom surface. The cover surface remains free of the material of the base body.According to at least one embodiment, a method for producing a connection carrier or an optoelectronic component is specified, having the steps:providing a base body which is formed with a plastic material,applying a conductor track, which has a base surface facing the base body, a cover surface facing away from the base body and a side surface connecting the base surface and the cover surface, to an upper side of the base body,heating the conductor track, so that by means of heat transfer from the conductor track to the base body the plastic material of the base body in the vicinity of the conductor track softens and the conductor track is surrounded in particular laterally by the base body, which leads to an increase in the adhesion.These method steps can be carried out, for example, in the order indicated.The method is based, inter alia, on the consideration that the conductor track is selectively heated and softening, for example melting or melting, of the material of the base body takes place only indirectly via the conductor track. In this way, the base body is hardly thermally stressed and in particular is not softened, melted or melted over its entire surface.In this way, it is possible, for example, to obtain an optical property of the base body, for example the transparency in the visible range of the electromagnetic spectrum. Furthermore, the base body is materially modified and its shape is not changed. For example, no shrinkage takes place due to heating of the base body.That is, the total temperature of the base body is hardly increased by the selective heating of the conductor track. Locally, however, where the base body is in direct contact with the conductor track, heating takes place via the glass transition temperature or even via the melting temperature of the plastic material of the base body.According to at least one embodiment of the method, the heating is carried out by means of pulsed electromagnetic radiation, for which the main body is transmissive.For example, the heating is effected with the aid of flash light, which can be generated, for example, with a xenon lamp. The pulsed electromagnetic radiation is absorbed in the conductor track and leads there to heating. The main body is largely transmissive for the radiation and has a transparency for the radiation of greater than 90%, for example. In this way, no or hardly any heating of the base body by the electromagnetic radiation takes place.With the method, it is possible in particular to heat a plurality of conductor tracks simultaneously and to increase the adhesion to the base body in the described manner. For example, it is possible for the conductor tracks to sink into the base body and / or for a bead with material of the base body to form around the conductor tracks.According to at least one embodiment of the method, an optoelectronic component is attached to the top surface of the conductor track before the heating of the conductor track, wherein a mechanical and electrical connection of the optoelectronic component to the top surface takes place simultaneously with the heating. For this purpose, for example, a connecting material such as a solder material can be arranged between the cover surface and the optoelectronic component, which is melted during heating.This means that, for example, a soldering of the component can take place simultaneously with the improvement in the adhesion of the conductor track in the base body. This results in an optoelectronic component in which, in a load test under the action of shear forces, the optoelectronic component detaches from the conductor track rather than the conductor track detaching from the base body. This means that the anchoring of the conductor track in the base body is mechanically more stable than the soldered connection between the component and the conductor track. In this way, a mechanically particularly stable component is specified.As an alternative to the described method, it is also possible for the connection carrier to be produced first in the described manner and for the optoelectronic component to be subsequently fastened to the connection carrier. In this case, the mechanical and electrical connection can then also be effected, as an alternative to a soldering method, by means of an adhesive method. It is also possible for the strip conductor to be heated by targeted sweeping over with a laser beam which specifically heats the strip conductor.In the following, the connection carrier described here, the optoelectronic component described here and the methods described here are explained in more detail on the basis of exemplary embodiments and the associated figures.On the basis of the schematic sectional representations of FIGS. 1, 2, 3, 4, a first exemplary embodiment of a method described here is explained in more detail.On the basis of the schematic sectional illustration of FIG. 4, an exemplary embodiment of an optoelectronic component described here is explained in more detail.With reference to the schematic sectional illustration of FIGS. 5, 6 and 7, a further exemplary embodiment of a method described here is explained in more detail.On the basis of the schematic plan view of FIG. 8, an exemplary embodiment of an optoelectronic component described here and an exemplary embodiment of a connection carrier described here are explained in more detail.Identical, similar or identically acting elements are provided with the same reference numerals in the figures. The figures and the proportions of the elements shown in the figures with respect to one another are not to be considered as true to scale. Rather, individual elements may be represented with exaggerated size for better clarity and / or for better understanding.FIG. 1 shows a schematic sectional illustration of a base body 1. The base body 1 can be designed, for example, as a film and is largely transmissive, for example transparent, to visible light.On an upper side 1 aof the base body 1, conductor tracks 2 are arranged. The conductor tracks 2 each comprise a base surface 2 afacing the base body, a cover surface 2 bfacing away from the base surface 2 a, and a side surface 2 cconnecting the cover surface and the base surface to one another.The conductor tracks 2 are formed, for example, with copper and have a width d of at most 500 μm, in particular of at least 5 μm and at most 60 μm (in this respect, compare also FIG. 8 ).In conjunction with FIG. 2, a further method step is shown. In this method step, the conductor tracks 2 are heated by means of electromagnetic radiation 6, which is generated by a radiation source 5.The radiation source 5 is, for example, a xenon flash lamp and the electromagnetic radiation 6 is corresponding light.The electromagnetic radiation 6, which is predominantly absorbed in the conductor tracks 2, but not in the main body 1, which is transmissive for the electromagnetic radiation 6, heats the conductor tracks 2. regions of the main body 1 in the immediate vicinity of the conductor tracks 2 are heated to a temperature which is high compared to the glass transition temperature of the plastic material of the main body 1.As shown schematically in the sectional illustration of FIG. 3, the conductor tracks 2 thereby sink into the base body 1 in such a way that, in addition to the base surface 2 aof the conductor tracks 2, the side surfaces 2 cof the conductor tracks 2 are now also in direct contact with the base body. Alternatively or additionally to sinking in, a bead made of material of the base body can form on the side surfaces 2 c.In a next method step, FIG. 4, an optoelectronic component 3 can be mechanically and electrically fastened to the connection carrier 10 by means of a connecting material 4. The connecting means 4 can be a soldering material or an electrically conductive adhesive. The optoelectronic component 3 can be, in particular, a light-emitting diode, for example a micro-LED.On the basis of the alternative embodiment of the method illustrated in the schematic sectional illustrations of FIGS. 5, 6 and 7, a method is described in which the production of the connection carrier 10 and the production of the optoelectronic component 20 take place simultaneously.For this purpose, the optoelectronic component 3 is applied to the top surface 2 bof the conductor tracks before heating, wherein a precursor of the connecting means 4 is introduced between the component 3 and the conductor tracks 2. For example, this is a solder paste which is introduced between the component 3 and the conductor track 2.In the subsequent method step, FIG. 6, heating of the conductor tracks and of the connecting means takes place simultaneously, so that the mechanical and electrical connection of the optoelectronic component on the cover surface takes place simultaneously with the heating of the conductor track.This in turn results in an optoelectronic component as is illustrated in FIG. 7.The schematic plan view of FIG. 8 shows a connection carrier 10, in which a plurality of conductor tracks 2 are applied to the base body 1 in a network-like manner. The side surfaces 2 cof the conductor tracks 2 are respectively wetted by material of the base body 1, the cover surface 2 bof the conductor tracks 2 remains free of the material of the base body. Furthermore, the optoelectronic component 3 is fastened to the connection carrier 10 by means of the connecting material 4.The invention is not limited to the exemplary embodiments by the description on the basis of the exemplary embodiments. Rather, the invention comprises any novel feature and any combination of features, which includes in particular any combination of features in the patent claims, even if this feature or this combination itself is not explicitly stated in the patent claims or exemplary embodiments.List of reference characters1 Main body 1 a Oberseite side 2 Interconnect 2 a Bodenfläche surface 2 b Deckfläche surface 2 c Seitenfläche surface 3 Optoelectronic component 4 Connecting material 5 Radiation source 6 Electromagnetic radiation 10 Connection carrier 20 Optoelectronic component d Width

Claims

Connection carrier (10) having - a base body (1) which is formed with a plastics material, - a conductor track (2) which has a base surface (2a) facing the base body (1), a cover surface (2b) facing away from the base body (1) and a side surface (2c) connecting the base surface (2a) and the cover surface (2b), wherein - the conductor track (2) is in direct contact with the base body (1) at the base surface (2a) and the side surface (2c).Connection carrier (10) according to the preceding claim, in which the side face (2c) is at least 50% or completely covered with the plastic material and the cover face (2b) is free of the plastic material.Connection carrier (10) according to one of the preceding claims, in which the conductor track (2) is printed on the base body.Connection carrier (10) according to one of the preceding claims, in which the base body (1) is radiation-transmissive.Connection carrier (10) according to one of the preceding claims, in which the conductor track (2) contains copper or consists of copper.Connection carrier (10) according to one of the preceding claims, having a multiplicity of conductor tracks (2).Connection carrier (10) according to one of the preceding claims, having a multiplicity of conductor tracks (2) which are arranged in the manner of a network.Optoelectronic component (20) having - a connection carrier (10) according to one of the preceding claims and - an optoelectronic component (3) which is connected to the connection carrier (10) in a mechanically and electrically conductive manner on the cover surface (2b) of the conductor track (2).Optoelectronic component (20) according to the preceding claim, in which the optoelectronic component (3) is or comprises a micro or mini LED.Method for producing a connection carrier (10) or an optoelectronic component (20), comprising the steps of: - providing a base body (1) which is formed with a plastics material, - applying a conductor track (2) which has a base surface (2a) facing the base body (1), a cover surface (2b) facing away from the base body (1) and a side surface (2c) connecting the base surface (2a) and the cover surface (2b), to an upper side (1a) of the base body (1), - heating the conductor track (2), so that by means of heat transfer from the conductor track (2) to the base body (1) the plastics material of the base body (1) softens in the vicinity of the conductor track (2) and the conductor track (2) has improved adhesion to the base body (1).Method according to the preceding claim, in which the heating is effected by means of pulsed electromagnetic radiation, for which the base body (1) is transmissive.Method according to one of the preceding claims, in which a multiplicity of conductor tracks (2) are heated simultaneously.Method according to one of the preceding claims, in which, before the heating of the conductor track (1), an optoelectronic component (3) is attached to the cover surface (2b) of the conductor track (2), wherein a mechanical and electrical connection of the optoelectronic component (3) to the cover surface (2b) takes place simultaneously with the heating of the conductor track (2).Method according to the preceding claim, in which a connecting material (4) which is arranged between the cover surface (2b) and the optoelectronic component (3) is melted during heating.Method according to one of the preceding claims, in which a connection carrier (10) according to Claims 1 to 7 or an optoelectronic component (20) according to Claims 8 or 9 is produced.

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